Spinning wheel covers in a variety of designs have been made for many years. However, despite improvements in bearings and control methods, the spinning wheel covers continue to have the problems of inconsistent and limited duration motion caused by airflow and bearing friction. Typically, conventional spinning wheel covers are designed to have high rotational inertia, relying on inertia either to hold the wheel cover stationary relative to the chassis while the vehicle is speeding up and in motion, or to keep the wheel cover in motion while the vehicle slows down or stops.
While motorized spinning wheel cover systems exist, the motion effects they are capable of producing may not be distinguishable from the motion effects of a free spinning wheel cover. As an example, a conventional free-spinning wheel cover system continues to rotate for a few minutes after a vehicle comes to a stop, particularly if the vehicle was previously traveling at high speed. A bystander will observe the wheel cover continuing to rotate while the vehicle is stopped and may note the visual impact since it will appear that the wheel is continuing to rotate even while the vehicle is stopped. Continuous motion of a wheel cover when a vehicle is stopped may no longer carry the visual impact or novelty that it once did. Continuous wheel cover motion provided by a motor simply extends the period of motion which, to a bystander without knowledge that the wheel cover is motor driven, may carry little or no visual distinction from a free spinning wheel cover.
Additionally, because existing designs lack a speed sensor and feedback control means or a means for precise open-loop speed control, they may not provide accurate speed control of the wheel cover due to the highly variable loads that are placed on the motor by changes in airflow due to vehicle speed, due to the sometimes accelerating frame of reference of the motor and due to variations in the inertia of the spinning wheel cover due to different aesthetic designs.
One desirable visual effect is of “Floating”. “Floating” occurs when the motor drives the wheel cover in the direction opposite the rotation of the wheel, but with a rotational speed of equal magnitude. “Floating” may give the accurate appearance that the wheel cover is rotationally fixed even though the vehicle wheels are rotating and therefore provides exceptional viewing pleasure to bystanders. Effective execution of the “Floating” visual effect may be achieved through accurate speed control of the motor.
Additionally, existing motorized spinning wheel cover systems do not provide a means for position control of the wheel cover since they lack a position sensor and feedback control loop or a means for open loop position control. It should also be noted that existing methods of driving a spinning wheel cover with a motor may produce little new or unique visual impact without also having the ability to produce wheel cover motions that are distinct from those of free spinning wheel covers. It may be desirable to provide a spinning wheel cover system capable of producing a large range distinct motions that may be produced if the system can precisely and consistently control position of the wheel cover.
Furthermore, the safety of conventional spinning wheel cover systems is lacking. High inertia spinning wheel covers may cause bodily harm to a bystander that comes in contact with them or other safety hazards. It is therefore desirable to stop a spinning wheel cover before a contact occurs.
Batteries mechanically coupled to the vehicle wheel to power wheel based electrical systems may be disadvantageous in many cases, for example: they require recharging facilities and procedures, may add significant un-sprung weight, require a specialized wheel, are run-time limited, and may be power limited. In the case of a spinning wheel system, a wheel-coupled battery may limit motor power and therefore the ability to use high acceleration rates and high duty cycles to produce visual effects that may be differentiated from a conventional free spinning wheel cover.
While electrical slip ring systems for transmitting power to a rotating vehicle wheel have existed for many years, they have failed to provide a design that can be easily adapted to a wide range of vehicles and vehicle wheels as well as a convenient, robust and adaptable method of making an electrical connection between the slip ring assembly and the electrical device mounted on the wheel, and other beneficial methods that may be apparent to one of ordinary skill in the art. Various factors may increase the cost and complexity of typical slip rings, such as: contact configuration, vehicle geometry, seals, and other related factors. Typical slip ring designs may be tailored to a particular vehicle model to avoid interference with the differing vehicle geometry such as drive shafts, wheels, brake calipers, and outboard suspension assemblies of different vehicles. The cost of slip rings may remain expensive due to the manufacturing and structural techniques that require a large volume of copper based alloy material for implementation of the rings Disc brake calipers on modern vehicles, and also may pose packaging problems because of the low clearance between the wheel and the caliper. To extend slip ring lifetime, complex seals and wipers are introduced to prevent contamination of the slip ring surface. Accordingly, aspects of the invention may overcome the forgoing limitations of the prior art and other limitations of the prior art that may be apparent to one of ordinary skill in the art.